Allison 1000/2000 Deep Pan Filter & Gasket Kit, Duramax

This is the deep-pan service set for the Allison 1000 and 2000 Series behind the 6.6L Duramax, not the shallow-pan version. If the truck runs an aftermarket or factory deep transmission pan, the standard short internal filter leaves the pickup sitting an inch off the bottom of the sump and the pump can pull air on hard launches and grades. This kit carries the long deep-style internal filter (GM 29542824) that reaches down to the deep-pan floor, plus the external spin-on filter (GM 29539579) and a new pan gasket, so a full fluid and filter service is one part number instead of three.

Fitment is Chevrolet Silverado 2500HD and 3500HD and GMC Sierra 2500HD and 3500HD, 2010 through 2019, with the Allison 1000/2000 five- and six-speed and a deep pan. It replaces the internal filter 29542824 and the spin-on 29539579. The pan gasket is a molded NBR rubber piece with pre-punched bolt holes, so it drops onto the pan rail and seals without RTV.

On the bench or under the truck: drop the pan, pull the old internal filter straight down off the pump pickup and set the new one until the seal seats squarely in the bore, lay the gasket dry on the pan rail, and torque the pan bolts evenly in a crossing pattern. Spin the external filter on by hand, snug it a turn past contact, then refill and check level hot. Do not reuse the old internal filter seal - that seal is the whole reason the pump holds prime.

Run it as maintenance on a towing or hot-shot truck, or any time you convert to a deep pan and need the correct longer pickup filter. The deep filter and the fresh pan gasket together are what stop the aeration, foaming, and slow-shift complaints that come from running a short filter in a deep sump.